WO 01/89885 discloses a gas generator. In such a system, the products of combustion of the primary pyrotechnic compound entail the decomposition of a secondary compound. The primary compound is contained in a primary chamber associated with an initiator provided with a reinforcing charge. At least one interaction of the products of combustion of the primary compound and those of the secondary compound occurs through an oxidation-reduction reaction in a slightly confined volume. Slightly confined volume means a volume so that the pressure of the gases reacting in such volume is less than a few hundred bars. For example, such slightly confined volume may be composed by a first zone of a secondary chamber, a second zone of which contains the secondary compound. Orifices for discharging gases are provided around such reaction zone. Advantageously, the reaction zone is arranged between the primary chamber and the secondary compound storage zone.
In a preferred construction of WO '885, the secondary compound is in the form of a powdery solid compound, generally ammonium nitrate. Now, a risk exists that the powder might be ejected through the orifices for discharging the gases prior to the total decomposition of the secondary compound.
It could therefore be helpful to improve the gas generator described in WO '885 to prevent such risk.